CVE-2025-63951 identifies a critical insecure deserialization vulnerability in the rss-mp3.php script of the MiczFlor RPi-Jukebox-RFID project, introduced in commit 4b2334f0ae0e87c0568876fc41c48c38aa9a7014 dated October 7, 2025. The vulnerability stems from the direct use of the 'rss' GET parameter as input to PHP's unserialize() function without any validation or sanitization. This allows a remote attacker, without any authentication, to craft malicious serialized PHP objects and inject them via the 'rss' parameter. When the application unserializes this data, it processes the injected objects, which can lead to application errors or denial of service conditions. The vulnerability does not require user interaction and can be triggered remotely. Although no known exploits are reported in the wild, the nature of insecure deserialization vulnerabilities often allows attackers to execute arbitrary code or disrupt service, depending on the application context. The affected software, MiczFlor RPi-Jukebox-RFID, is an open-source project typically deployed on Raspberry Pi devices for media playback with RFID integration, often used in hobbyist or small-scale IoT environments. The lack of a CVSS score limits precise severity quantification, but the vulnerability's characteristics indicate a high risk. No patches or mitigation links are currently provided, emphasizing the need for immediate developer attention to validate or avoid unserialize() on untrusted input. This vulnerability highlights the risks of insecure deserialization in PHP applications, especially in embedded or IoT projects where security controls may be limited.

For European organizations, the primary impact of CVE-2025-63951 is the potential for denial of service on devices running the vulnerable MiczFlor RPi-Jukebox-RFID software. This could disrupt media playback services or related IoT functionalities, particularly in environments where these devices are used for automation, public information kiosks, or interactive installations. While no remote code execution is explicitly confirmed, insecure deserialization vulnerabilities often carry that risk, which could lead to further compromise of the device or network if exploited. The vulnerability requires no authentication and can be triggered remotely, increasing the attack surface. Organizations relying on Raspberry Pi-based IoT solutions in sectors such as education, retail, or cultural institutions across Europe could face operational disruptions. Additionally, the lack of patches means that vulnerable devices remain exposed until developers or users implement mitigations. The impact on confidentiality is limited unless further exploitation is possible, but integrity and availability are at risk due to potential application errors or service outages. Given the growing adoption of IoT devices in Europe, this vulnerability could affect a broad range of small-scale deployments, especially in countries with active maker communities and IoT innovation hubs.

To mitigate CVE-2025-63951, developers and users of the MiczFlor RPi-Jukebox-RFID project should immediately avoid passing untrusted input directly to PHP's unserialize() function. Specifically, the 'rss' GET parameter must be validated rigorously to ensure it contains only safe, expected data formats before deserialization. Alternatively, replace the use of unserialize() with safer data handling methods such as JSON parsing, which does not allow object injection. Implement input sanitization and strict type checking to prevent malicious payloads. If possible, apply application-level whitelisting of acceptable input values. Network-level mitigations can include restricting access to the vulnerable endpoint via firewalls or VPNs to trusted users only. Monitoring logs for unusual requests to rss-mp3.php can help detect exploitation attempts. Since no official patches are available, users should track the project repository for updates or consider forking the project to implement secure deserialization practices. Finally, segment IoT devices from critical networks to limit potential impact if exploitation occurs.